Bioremediation of hydrocarbon-contaminated polar soils
ABSTRACT Bioremediation is increasingly viewed as an appropriate remediation technology for hydrocarbon-contaminated polar soils. As for all soils, the successful application of bioremediation depends on appropriate biodegradative microbes and environmental conditions in situ. Laboratory studies have confirmed that hydrocarbon-degrading bacteria typically assigned to the genera Rhodococcus, Sphingomonas or Pseudomonas are present in contaminated polar soils. However, as indicated by the persistence of spilled hydrocarbons, environmental conditions in situ are suboptimal for biodegradation in polar soils. Therefore, it is likely that ex situ bioremediation will be the method of choice for ameliorating and controlling the factors limiting microbial activity, i.e. low and fluctuating soil temperatures, low levels of nutrients, and possible alkalinity and low moisture. Care must be taken when adding nutrients to the coarse-textured, low-moisture soils prevalent in continental Antarctica and the high Arctic because excess levels can inhibit hydrocarbon biodegradation by decreasing soil water potentials. Bioremediation experiments conducted on site in the Arctic indicate that land farming and biopiles may be useful approaches for bioremediation of polar soils.
- SourceAvailable from: Alexandra B. Ribeiro[Show abstract] [Hide abstract]
ABSTRACT: A 168-day period field study, carried out in Sisimiut, Greenland, assessed the potential to enhance soil remediation with the surplus heating from an incineration facility. This approach searches a feasible ex situ remediation process that could be extended throughout the year with low costs. Individual and synergistic effects of biostimulation were also tested, in parallel. An interim evaluation at the end of the first 42 days showed that biostimulation and active heating, as separate treatments, enhanced petroleum hydrocarbon (PHC) removal compared to natural attenuation. The coupling of both technologies was even more effective, corroborating the benefits of both techniques in a remediation strategy. However, between day 42 and day 168, there was an opposite remediation trend with all treatments suggesting a stabilization except for natural attenuation, where PHC values continued to decrease. This enforces the "self-purification" capacity of the system, even at low temperatures. Coupling biostimulation with active heating was the best approach for PHC removal, namely for a short period of time (42 days). The proposed remediation scheme can be considered a reliable option for faster PHC removal with low maintenance and using "waste heating" from an incineration facility.Environmental Science and Pollution Research 02/2014; DOI:10.1007/s11356-013-2466-3 · 2.76 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Antarctica's ice-free environments span diverse habitats, ranging from well developed and nutrient rich soils in the coastal areas, to poorly developed and oligotrophic soils in the continent's deserts and high elevation sites. Though most terrestrial environments in Antarctica are typified by harsh environmental condi-tions, many soils are home to abundant and diverse bacterial communities. These communities are locally adapted, varying both between and within different regions of the continent, and typically reflecting the local physicochemical and biological characteristics of the soils. Environmental conditions are changing rapidly in many areas, due to increased human activity on the continent and the impacts of climate change. This chapter reviews characteristics of bacterial communities in soils across Antarctica in relation to their environment, and dis-cusses the potential responses of bacterial communities to contemporary envi-ronmental change. Continued and coordinated efforts to understand bacterial community structure and function in Antarctic soils will be necessary to monitor and predict ecological responses in these changing environments, and to shape management practices that will ensure the protection and preservation of biodi-versity in Antarctica's terrestrial ecosystems. 2.1 Introduction While the majority of continental Antarctica is permanently covered by the Ant-arctic Ice Sheet, approximately 0.35 % of the continent remains free from ice and snow cover for part or all of the year (Hopkins et al. 2006b). These ice-free areas are largely confined to the perimeter of the continent at coastal sites and regions cut offAntarctic Terrestrial Microbiology: Physical and biological properties of Antarctic soils, Edited by Don A Cowan, 01/2014: pages 9-33; Springer-Verlag, Berlin..
- [Show abstract] [Hide abstract]
ABSTRACT: EXTENDED ABSTRACT The capability of Antarctic microorganisms, including filamentous fungi to exist in some of the most severe climatic conditions known to Earth is the reason of the increasing interest to their metabolic characteristics. The study of species diversity characteristic of this region, and their metabolic capabilities can be useful when searching for new solutions in the industry and the environment. The aim of this study was to test the possible ability of new isolated Antarctic fungal strains to grow and develop on phenanthrene, anthracene, and naphthalene as sole carbon and energy sources in the medium. Sixteen fungal strains isolated from Livingston Island – Antarctica were studied for their ability to degrade phenanthrene, naphthalene and anthracene. Cultures were stored on beer agar medium, pH 6.3 in glass vials with screw caps at 4°C. The strains were grown in a solid or liquid mineral medium Czapek Dox containing 10 g/l glucose and/or various concentrations of the investigated polycyclic aromatics. The temperature of cultivation was 23°C. In the solid medium experiments a spray-plate technique was applied. PAH were distributed evenly as a thin visible overlay by pipetting 0.6 ml of a filter-sterilized acetone solution (0.5%) and stirred up on the agar surface. Plates were dried overnight at 30 °C to allow the acetone evaporation. In experiments in liquid media PAH were ultra sounded ex tempore to a fine dispersion in small aliquots of liquid medium and then inoculated in the corresponding cultivating media. Although there were found five representatives of Penicillium and Aspergillus which did not show any development in the presence of such compounds most of the investigated strains demonstrated good tolerance to the presence of anthracene and naphthalene. A good tolerance to phenanthrene in the culture medium was obtained only for Alternaria maritima strain AL10. Two other strains: Aspergillus glaucus AL1 and Penicillium waksmanii AL14 showed slight growth in phenanthrene presence. The degradation experiments carried out in a media containing each one of the tested compounds as a single source of carbon and energy demonstrated the ability of Penicillium rugolosum AL7 and Penicillium waksmanii AL14 to degrade 0.3 g/l anthracene. Strains Alternaria maritima AL10 and Penicillium waksmanii AL14 showed capacity to utilize 0.3 g/l phenanthrene. Aspergillus fumigatus AL9, Penicillium chrysogenum AL12 and Mucor sp. AL13 degraded 0.3 g/l naphthalene. As a result of the research it could be concluded that the most toxic effect was exerted by phenanthrene followed by anthracene, and naphthalene. We see also that different species of fungi genera show different abilities to adapt and to utilize each one of the polycyclic aromatic compounds used in this study.the 13th International Conference of Environmental Science and Technology, September 2013, Athens, Greece; 09/2013